Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
import java.io.DataInputStream; 
import java.io.FileInputStream; 
import java.io.IOException; 
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner; 
import java.util.StringTokenizer;  
import java.util.*;
import java.io.*;
 
public class Main 
  {
   static class Reader 
   { 
       final private int BUFFER_SIZE = 1 << 16; 
       private DataInputStream din; 
       private byte[] buffer; 
       private int bufferPointer, bytesRead; 
 
       public Reader() 
       { 
           din = new DataInputStream(System.in); 
           buffer = new byte[BUFFER_SIZE]; 
           bufferPointer = bytesRead = 0; 
       } 
 
       public Reader(String file_name) throws IOException 
       { 
           din = new DataInputStream(new FileInputStream(file_name)); 
           buffer = new byte[BUFFER_SIZE]; 
           bufferPointer = bytesRead = 0; 
       } 
 
       public String nextLine() throws IOException 
       { 
           byte[] buf = new byte[100000000]; // line length 
           int cnt = 0, c; 
           while ((c = read()) != -1) 
           { 
               if (c == '\n') 
                   break; 
               buf[cnt++] = (byte) c; 
           } 
           return new String(buf, 0, cnt); 
       } 
 
       public int nextInt() throws IOException 
       { 
           int ret = 0; 
           byte c = read(); 
           while (c <= ' ') 
               c = read(); 
           boolean neg = (c == '-'); 
           if (neg) 
               c = read(); 
           do
           { 
               ret = ret * 10 + c - '0'; 
           }  while ((c = read()) >= '0' && c <= '9'); 
 
           if (neg) 
               return -ret; 
           return ret; 
       } 
 
       public long nextLong() throws IOException 
       { 
           long ret = 0; 
           byte c = read(); 
           while (c <= ' ') 
               c = read(); 
           boolean neg = (c == '-'); 
           if (neg) 
               c = read(); 
           do { 
               ret = ret * 10 + c - '0'; 
           } 
           while ((c = read()) >= '0' && c <= '9'); 
           if (neg) 
               return -ret; 
           return ret; 
       } 
 
       public double nextDouble() throws IOException 
       { 
           double ret = 0, div = 1; 
           byte c = read(); 
           while (c <= ' ') 
               c = read(); 
           boolean neg = (c == '-'); 
           if (neg) 
               c = read(); 
 
           do { 
               ret = ret * 10 + c - '0'; 
           } 
           while ((c = read()) >= '0' && c <= '9'); 
 
           if (c == '.') 
           { 
               while ((c = read()) >= '0' && c <= '9') 
               { 
                   ret += (c - '0') / (div *= 10); 
               } 
           } 
 
           if (neg) 
               return -ret; 
           return ret; 
       } 
 
       private void fillBuffer() throws IOException 
       { 
           bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
           if (bytesRead == -1) 
               buffer[0] = -1; 
       } 
 
       private byte read() throws IOException 
       { 
           if (bufferPointer == bytesRead) 
               fillBuffer(); 
           return buffer[bufferPointer++]; 
       } 
 
       public void close() throws IOException 
       { 
           if (din == null) 
               return; 
           din.close(); 
       } 
   } 
public static  int gcd(int a,int b){
        if(b==0)
            return a;
        return gcd(b,a%b);
    }
   public static void main(String[] args) throws IOException 
   { 
       Reader sc=new Reader();
       /*String qqqq=sc.nextLine();
       char c=qqqq.charAt(0);*/
       String s=sc.nextLine();
       /*String s="";
       String[] qqq=sc.nextLine().split(" ");
       s=qqq[0];*/
       
        Set<Character> set = new HashSet<Character>();
        for(char c: s.toCharArray()) {
            if(c >= 'a' && c <= 'z') {
                set.add(c);
            }
        }
        System.out.println(set.size());
  }
  
  }